It is recognized that the repair of superalloy materials is made difficult due to their susceptibility to weld solidification cracking and strain age cracking. The term “superalloy” is used herein as it is commonly used in the art; i.e., a highly corrosion and oxidation resistant alloy that exhibits excellent mechanical strength and resistance to creep at high temperatures. Superalloys typically include a high nickel or cobalt content. Examples of superalloys include alloys sold under the trademarks and brand names Hastelloy, Inconel alloys (e.g. IN 738, IN 792, IN 939), Rene alloys (e.g. Rene N5, Rene 80, Rene 142), Haynes alloys, Mar M, CM 247, CM 247 LC, 0263, 718, X-750, ECY 768, 282, X45, PWA 1483 and CMSX (e.g. CMSX-4) single crystal alloys.
It is known to repair superalloy gas turbine engine components using a presintered preform containing a mixture of base alloy particles having a composition similar to the alloy of the component, braze alloy particles containing a melting point depressant such as boron or silicon, and a binder. See for example U.S. Pat. No. 8,087,565 B2. However, boron and silicon create deleterious phases which reduce the ductility of the joint and repaired region. Boron and silicon free braze alloys incorporating hafnium and/or zirconium have been developed, however, such materials tend to form carbides at the braze joint. Thus, further improvements in the repair of superalloy materials are desired.